Hey Ric, glad to see you made it here. Weren't you asking about these batteries a couple months ago?

I have a pack from batteryspace made of their 9AH D cells .. I got the pack a couple years ago and they may have improved the cells since then .. e.g. mine is rated at 9 AH while now they're rated at 10 AH. I notice they list the rating as so:

Standard rate: 10Amp ( Recommended and warrantied)

Highest rate for continuous running: 30Amp

Max. Rate for short time: 50Amp ( Not recommend as working rate )

Discharge rates above 1C (you're talking about 3C) is not recommended and warrantied. I'm interpreting it to mean you shouldn't do it on a regular basis and that the farther above a 10 amp rate you go the dicier it will be. Even their F cell pack has the recommended and warranted rate at only 13 amp.

My experience with the pack I have is .. I tried using it on my bike with a wilderness energy 36v 35 amp brushed system. This is the same bike I showed you last fall at the EV rally, that I showed you with a pair of DeWalt packs for it. With the batteryspace 9AH pack, the pack would get very VERY hot when discharging at the highest rate (35 amp controller .. but I don't know the actual discharge rate) and sometimes it did not properly charge up after a discharge like that.

I recall that ChasB has an F cell pack from batteryspace and last year he was very happy with it.